The conventional quark model presents part of the properties of QCD in agreement with experimental data up to 2003 in which the first exotic hadron candidate \(X(3872)\)  was observed by Belle Collaboration [1]}. According to quark model, hadrons can be classified into two groups: mesons made of quark-antiquark pair and baryons made of three quarks. The spectrum of QCD is more richer than the spectrum of conventional quark model since any color neutral (colorless) configuration is possible in QCD.
